W9XBK, WBKB - Chicago

W9XBK was the second electronic station on the air in Chicago, starting transmission in 1939. (the first was W9XZV, Zenith Radio Corporation's experimental outlet on channel 1), W9XBK transmitted at 60-66 megacycles, then television's channel 2.  Balaban & Katz also held the experimental television licenses for W9XBT, W9XBB, and W9XPR. When the VHF frequencies were changed by the FCC, W9XBK found itself transmitting at 66-72 megacycles, the current channel 4.  W9XZV ended up on channel 2.  Late in 1943, the station would become the first commercial station in Chicago, WBKB.  Here is a story at Chicago Television about WBKB, and an article about a program created in 1947.